| Summary: | 碩士 === 國立中興大學 === 材料工程學研究所 === 90 === Interfacial reactions and microstructural analysis of the Sn/Zn and Zn (electroplated)/Cu binary systems, and Sn (electroplated)/Zn (electroplated)/Cu, and Sn-9Zn/Cu ternary systems upon heat treatment at 200, 250, and 300℃ for 5 and 30 min in formic acid atmosphere are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM) and field-emission scanning electron microscopy (FE-SEM).
In the case of the Sn/Zn system, the result shows that Zn dissolves into Sn and forms an eutectic layered structure, upon heat treatment of the specimen at 300℃for 5 min; whereas in the system of Zn (electroplated)/Cu, a new intermetallic compound, γ-Cu5Zn8, was formed at the Zn/Cu interface upon annealing at 200, 250, and 300℃ for 5 min. In the Sn (electroplated)/Zn (electroplated)/Cu ternary system heat-treated at 200℃、250℃and 300℃for 5 min, it is observed that Cu diffuses into the Zn layer and forms theγ-Cu5Zn8 intermetallic phase. As the heat treatment temperature was raised to 300℃, it is found that Sn diffuses into the Cu5Zn8 layer and a (Cu1-x Snx)5Zn8 phase was produced. In contrast, only theγ-Cu5Zn8 phase is detected in the Sn-Zn/Cu ternary system for the specimens heat-treated at 250 and 300℃ for 5 and 30 min, and the thickness of the intermetallic layer increases with temperature and annealing time.
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